I'm not so sure that's true, 27" at 1920x1080 is just not a nice as a 24" imo, however if you can afford to buy something like the Dell U2711 which has a resolution of 2560x1440 then ...maybe yea.
I consider 22-24" to be the best place to be, unless you can afford to buy the high res IPS 27-30" displays ...however consider that for that kind of display you need a bit more space too.
For that price, unless you specifically require lots of extra inputs, the
LG IPS231P-BN is the best display you can get, it's a vastly superior IPS panel rather than a TN. Until this LG came out, it was preciously unheard of to get an IPS display for much less than about 250 pounds. Also don't undervalue the usefulness of a height adjustable stand (not relevant if you have a VESA arm or monitor stand I suppose).